1/* Functions for writing LTO sections.
2
3 Copyright (C) 2009-2024 Free Software Foundation, Inc.
4 Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 3, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3. If not see
20<http://www.gnu.org/licenses/>. */
21
22#include "config.h"
23#include "system.h"
24#include "coretypes.h"
25#include "backend.h"
26#include "rtl.h"
27#include "tree.h"
28#include "gimple.h"
29#include "cgraph.h"
30#include "data-streamer.h"
31#include "langhooks.h"
32#include "lto-compress.h"
33#include "print-tree.h"
34
35static vec<lto_out_decl_state_ptr> decl_state_stack;
36
37/* List of out decl states used by functions. We use this to
38 generate the decl directory later. */
39
40vec<lto_out_decl_state_ptr> lto_function_decl_states;
41
42
43/*****************************************************************************
44 Output routines shared by all of the serialization passes.
45*****************************************************************************/
46
47
48/* Flush compressed stream data function, sends NUM_CHARS from CHARS
49 to the append lang hook, OPAQUE is currently always NULL. */
50
51static void
52lto_append_data (const char *chars, unsigned int num_chars, void *opaque)
53{
54 gcc_assert (opaque == NULL);
55 lang_hooks.lto.append_data (chars, num_chars, opaque);
56}
57
58/* Pointer to the current compression stream. */
59
60static struct lto_compression_stream *compression_stream = NULL;
61
62/* Begin a new output section named NAME. If COMPRESS is true, zlib compress
63 the section. */
64
65void
66lto_begin_section (const char *name, bool compress)
67{
68 lang_hooks.lto.begin_section (name);
69
70 if (streamer_dump_file)
71 {
72 if (flag_dump_unnumbered || flag_dump_noaddr)
73 fprintf (stream: streamer_dump_file, format: "Creating %ssection\n",
74 compress ? "compressed " : "");
75 else
76 fprintf (stream: streamer_dump_file, format: "Creating %ssection %s\n",
77 compress ? "compressed " : "", name);
78 }
79 gcc_assert (compression_stream == NULL);
80 if (compress)
81 compression_stream = lto_start_compression (callback: lto_append_data, NULL);
82}
83
84
85/* End the current output section. */
86
87void
88lto_end_section (void)
89{
90 if (compression_stream)
91 {
92 lto_end_compression (stream: compression_stream);
93 compression_stream = NULL;
94 }
95 lang_hooks.lto.end_section ();
96}
97
98/* Write SIZE bytes starting at DATA to the assembler. */
99
100void
101lto_write_data (const void *data, unsigned int size)
102{
103 if (compression_stream)
104 lto_compress_block (stream: compression_stream, base: (const char *)data, num_chars: size);
105 else
106 lang_hooks.lto.append_data ((const char *)data, size, NULL);
107}
108
109/* Write SIZE bytes starting at DATA to the assembler. */
110
111void
112lto_write_raw_data (const void *data, unsigned int size)
113{
114 lang_hooks.lto.append_data ((const char *)data, size, NULL);
115}
116
117/* Write all of the chars in OBS to the assembler. Recycle the blocks
118 in obs as this is being done. */
119
120void
121lto_write_stream (struct lto_output_stream *obs)
122{
123 unsigned int block_size = 1024;
124 struct lto_char_ptr_base *block;
125 struct lto_char_ptr_base *next_block;
126 if (!obs->first_block)
127 return;
128
129 for (block = obs->first_block; block; block = next_block)
130 {
131 const char *base = ((char *)block) + sizeof (struct lto_char_ptr_base);
132 unsigned int num_chars = block_size - sizeof (struct lto_char_ptr_base);
133
134 /* If this is not the last block, it is full. If it is the last
135 block, left_in_block indicates how many chars are unoccupied in
136 this block; subtract from num_chars to obtain occupancy. */
137 next_block = (struct lto_char_ptr_base *) block->ptr;
138 if (!next_block)
139 num_chars -= obs->left_in_block;
140
141 if (compression_stream)
142 lto_compress_block (stream: compression_stream, base, num_chars);
143 else
144 lang_hooks.lto.append_data (base, num_chars, block);
145 free (ptr: block);
146 block_size *= 2;
147 }
148}
149
150/* Create the output block and return it. */
151
152struct lto_simple_output_block *
153lto_create_simple_output_block (enum lto_section_type section_type)
154{
155 struct lto_simple_output_block *ob
156 = ((struct lto_simple_output_block *)
157 xcalloc (1, sizeof (struct lto_simple_output_block)));
158
159 ob->section_type = section_type;
160 ob->decl_state = lto_get_out_decl_state ();
161 ob->main_stream = ((struct lto_output_stream *)
162 xcalloc (1, sizeof (struct lto_output_stream)));
163
164 return ob;
165}
166
167
168/* Produce a simple section for one of the ipa passes. */
169
170void
171lto_destroy_simple_output_block (struct lto_simple_output_block *ob)
172{
173 char *section_name;
174 struct lto_simple_header header;
175
176 section_name = lto_get_section_name (ob->section_type, NULL, 0, NULL);
177 lto_begin_section (name: section_name, compress: !flag_wpa);
178 free (ptr: section_name);
179
180 /* Write the header which says how to decode the pieces of the
181 t. */
182 memset (s: &header, c: 0, n: sizeof (struct lto_simple_header));
183 header.main_size = ob->main_stream->total_size;
184 lto_write_data (data: &header, size: sizeof header);
185
186 lto_write_stream (obs: ob->main_stream);
187
188 /* Put back the assembly section that was there before we started
189 writing lto info. */
190 lto_end_section ();
191
192 free (ptr: ob->main_stream);
193 free (ptr: ob);
194}
195
196
197/* Return a new lto_out_decl_state. */
198
199struct lto_out_decl_state *
200lto_new_out_decl_state (void)
201{
202 struct lto_out_decl_state *state = XCNEW (struct lto_out_decl_state);
203 int i;
204
205 for (i = 0; i < LTO_N_DECL_STREAMS; i++)
206 lto_init_tree_ref_encoder (encoder: &state->streams[i]);
207
208 /* At WPA time we do not compress sections by default. */
209 state->compressed = !flag_wpa;
210
211 return state;
212}
213
214
215/* Delete STATE and components. */
216
217void
218lto_delete_out_decl_state (struct lto_out_decl_state *state)
219{
220 int i;
221
222 for (i = 0; i < LTO_N_DECL_STREAMS; i++)
223 lto_destroy_tree_ref_encoder (encoder: &state->streams[i]);
224
225 free (ptr: state);
226}
227
228
229/* Get the currently used lto_out_decl_state structure. */
230
231struct lto_out_decl_state *
232lto_get_out_decl_state (void)
233{
234 return decl_state_stack.last ();
235}
236
237/* Push STATE to top of out decl stack. */
238
239void
240lto_push_out_decl_state (struct lto_out_decl_state *state)
241{
242 decl_state_stack.safe_push (obj: state);
243}
244
245/* Pop the currently used out-decl state from top of stack. */
246
247struct lto_out_decl_state *
248lto_pop_out_decl_state (void)
249{
250 return decl_state_stack.pop ();
251}
252
253/* Record STATE after it has been used in serializing the body of
254 FN_DECL. STATE should no longer be used by the caller. The ownership
255 of it is taken over from this point. */
256
257void
258lto_record_function_out_decl_state (tree fn_decl,
259 struct lto_out_decl_state *state)
260{
261 int i;
262
263 /* Strip all hash tables to save some memory. */
264 for (i = 0; i < LTO_N_DECL_STREAMS; i++)
265 if (state->streams[i].tree_hash_table)
266 {
267 delete state->streams[i].tree_hash_table;
268 state->streams[i].tree_hash_table = NULL;
269 }
270 state->fn_decl = fn_decl;
271 lto_function_decl_states.safe_push (obj: state);
272}
273

source code of gcc/lto-section-out.cc